1. Field of the Invention
The present invention relates generally to a liquid-based Pap test and, more particularly, to an apparatus and method for removing cells from an endocervical brush utilized to obtain a specimen for testing.
2. Description of Related Art
Detection and diagnosis of a variety of diseases, such as cancer, often involves the collection and microscopic examination of a cell sample. Such cell samples, as in the Papanicolaou (xe2x80x9cPapxe2x80x9d) test, are typically collected from a patient with a type of cytology sampling device. Such sampling devices include various types of brushes (e.g., the Cervix-brush made by Rovers of Oss, The Netherlands and the Cytobrush made by Medscand of Malmo, Sweden) and spatulas (e.g., the Szalay spatula made by C.S.M. Graf and Co., of Steinach Switzerland, the Papex spatula made by Hengstberger of Vienna Austria, and the WrGKK spatula utilized by the main social security in Vienna, Austria), as well as cotton swabs and loop-type devices.
In the case of brush type sampling devices, the cell samples must be transferred after collection from the bristles of the brush to a glass slide that allows for the examination of the cells. In order to obtain the best diagnosis, it is imperative that the cell samples be completely and accurately transferred from the brush to the testing medium. Not only can this affect the diagnosis, but women may be reluctant to have the procedure repeated when an inadequate sample is taken. It will be understood that an inadequate sample may include the instance where no abnormal cells are transferred to the glass slide, which results in false negatives that go unnoticed.
In particular, it will be appreciated that a liquid-based Pap test is growing in use by many doctors and labs. This involves the cell sample being transferred from the brush to a fixative or preservative within a vial or other container. One example of an FDA-approved liquid based preparation product is the ThinPrep(copyright) Pap Test(trademark) (xe2x80x9cTPPTxe2x80x9d) made by Cytyc Corporation of Boxborough, Massachusetts. As seen in the protocol for the TPPT, which is described in a ThinPrep(copyright) Pap Test Quick Reference Guide (1997), the brush is rotated vigorously while being pushed against the vial wall in order to release the cell sample in the solution. It will be appreciated, however, that pushing the cytology brush against the vial wall can have the detrimental effect of compacting the cell sample to the bristles. Additionally, the brush may not even touch the vial wall if the shaft of the brush is held in a certain way.
While the protocol set forth in the TPPT has been successful in gaining approval from the Food and Drug Administration. it has been found to be very operator dependent and results could be improved if a greater release of the cell sample from the brush is accomplished. One attempt at enhancing the transfer of a cell sample from a brush is disclosed in U.S. Pat. No. 5,422,273 to Garrison et al. As seen therein, the vial containing the fixative solution is constructed so as to include a plurality of fins therein. In this way, a surface is available against which the brush may be agitated or scraped when the brush is rotated. Although this approach may assist in dislodging cell sample from the brush bristles, the vial utilizing such fins is not without disadvantages. Most importantly, it will be recognized that the vial containing the fixative/cell sample undergoes a filtering process in a device known as a ThinPrep processor specially suited for such purpose and described in a manual entitled xe2x80x9cThinPrep(copyright) 2000 Operator Manual.xe2x80x9d Since the vial disclosed in the ""273 patent does not have smooth cylindrical walls and is not sized to accept the filter, it could not be utilized in the ThinPrep processor.
Accordingly, it is a primary object of the present invention to provide an apparatus and method that improves the harvesting of endocervical cells for testing in a liquid-based Pap test.
It is another object of the present invention to provide an apparatus and method that increases the number of cells obtained from an endocervical brush for testing in a liquid-based Pap test, as well as minimize the residual brush specimen.
It is still another object of the present invention to provide an apparatus and method with respect to a liquid-based Pap test that obtains more accurate results, reduces screening time by providing increased numbers of abnormal cells that are more readily located, and reduces the need for rescreening and retesting.
Yet another object of the present invention is to provide an apparatus and method that facilitates an increase in the detection rates for AGUS/AIS cases and squamous lesions in a liquid-based Pap test.
Another object of the present invention is to provide an apparatus and method that increases the archived volume of preserved cell suspension in a liquid-based Pap test for ancillary STD testing.
Still another object of the present invention is to provide an apparatus and method that facilitates harvesting of cells for a liquid-based Pap test so as to be less operator dependent.
These objects and other features of the present invention will become more readily apparent upon reference to the following description when taken in conjunction with the following drawings.
In accordance with a first aspect of the present invention, a device for collecting cervicovaginal cells is disclosed as including a first end portion for contacting an ectocervical region and obtaining a sampling of cells therefrom, a second end portion opposite the first end portion, and an elongated middle portion connecting the first and second end portions. A region is formed on the device that provides a designated edge against which an endocervical brush is able to be rubbed for harvesting of cells from the endocervical brush in a vial of preservative.
In accordance with a second aspect of the present invention, a device for assisting in the removal of transformation zone cells from an endocervical brush in a liquid-based system is disclosed as including a first end portion, a second end portion, and an elongated middle portion connecting the first and second end portions. A region is formed on the device that provides a designated edge against which the endocervical brush is able to be rubbed for harvesting of endocervical cells from the endocervical brush in a vial of preservative.
In accordance with a third aspect of the present invention. a method of harvesting cells from an endocervical brush in a liquid-based system is disclosed as including the steps of providing a vial at least partially filled with a designated preservative, placing a device in the vial so that a portion thereof is submerged in the designated preservative, where the device has a region formed therein that provides a designated edge, positioning the endocervical brush within the vial, orienting the endocervical brush with respect to the device, and moving the endocervical brush so that bristles thereof rub back and forth against the designated edge of the device.